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e57d8977 PG |
1 | /* SPDX-License-Identifier: GPL-2.0 */ |
2 | #ifndef __PERF_MUTEX_H | |
3 | #define __PERF_MUTEX_H | |
4 | ||
5 | #include <pthread.h> | |
6 | #include <stdbool.h> | |
7 | ||
bfa339ce IR |
8 | /* |
9 | * A function-like feature checking macro that is a wrapper around | |
10 | * `__has_attribute`, which is defined by GCC 5+ and Clang and evaluates to a | |
11 | * nonzero constant integer if the attribute is supported or 0 if not. | |
12 | */ | |
13 | #ifdef __has_attribute | |
14 | #define HAVE_ATTRIBUTE(x) __has_attribute(x) | |
15 | #else | |
16 | #define HAVE_ATTRIBUTE(x) 0 | |
17 | #endif | |
18 | ||
19 | #if HAVE_ATTRIBUTE(guarded_by) && HAVE_ATTRIBUTE(pt_guarded_by) && \ | |
20 | HAVE_ATTRIBUTE(lockable) && HAVE_ATTRIBUTE(exclusive_lock_function) && \ | |
21 | HAVE_ATTRIBUTE(exclusive_trylock_function) && HAVE_ATTRIBUTE(exclusive_locks_required) && \ | |
22 | HAVE_ATTRIBUTE(no_thread_safety_analysis) | |
23 | ||
24 | /* Documents if a shared field or global variable needs to be protected by a mutex. */ | |
25 | #define GUARDED_BY(x) __attribute__((guarded_by(x))) | |
26 | ||
27 | /* | |
28 | * Documents if the memory location pointed to by a pointer should be guarded by | |
29 | * a mutex when dereferencing the pointer. | |
30 | */ | |
31 | #define PT_GUARDED_BY(x) __attribute__((pt_guarded_by(x))) | |
32 | ||
33 | /* Documents if a type is a lockable type. */ | |
34 | #define LOCKABLE __attribute__((lockable)) | |
35 | ||
36 | /* Documents functions that acquire a lock in the body of a function, and do not release it. */ | |
37 | #define EXCLUSIVE_LOCK_FUNCTION(...) __attribute__((exclusive_lock_function(__VA_ARGS__))) | |
38 | ||
39 | /* | |
40 | * Documents functions that expect a lock to be held on entry to the function, | |
41 | * and release it in the body of the function. | |
42 | */ | |
43 | #define UNLOCK_FUNCTION(...) __attribute__((unlock_function(__VA_ARGS__))) | |
44 | ||
45 | /* Documents functions that try to acquire a lock, and return success or failure. */ | |
46 | #define EXCLUSIVE_TRYLOCK_FUNCTION(...) \ | |
47 | __attribute__((exclusive_trylock_function(__VA_ARGS__))) | |
48 | ||
49 | /* Documents a function that expects a mutex to be held prior to entry. */ | |
50 | #define EXCLUSIVE_LOCKS_REQUIRED(...) __attribute__((exclusive_locks_required(__VA_ARGS__))) | |
51 | ||
52 | /* Turns off thread safety checking within the body of a particular function. */ | |
53 | #define NO_THREAD_SAFETY_ANALYSIS __attribute__((no_thread_safety_analysis)) | |
54 | ||
55 | #else | |
56 | ||
57 | #define GUARDED_BY(x) | |
58 | #define PT_GUARDED_BY(x) | |
59 | #define LOCKABLE | |
60 | #define EXCLUSIVE_LOCK_FUNCTION(...) | |
61 | #define UNLOCK_FUNCTION(...) | |
62 | #define EXCLUSIVE_TRYLOCK_FUNCTION(...) | |
63 | #define EXCLUSIVE_LOCKS_REQUIRED(...) | |
64 | #define NO_THREAD_SAFETY_ANALYSIS | |
65 | ||
66 | #endif | |
67 | ||
e57d8977 PG |
68 | /* |
69 | * A wrapper around the mutex implementation that allows perf to error check | |
70 | * usage, etc. | |
71 | */ | |
bfa339ce | 72 | struct LOCKABLE mutex { |
e57d8977 PG |
73 | pthread_mutex_t lock; |
74 | }; | |
75 | ||
76 | /* A wrapper around the condition variable implementation. */ | |
77 | struct cond { | |
78 | pthread_cond_t cond; | |
79 | }; | |
80 | ||
81 | /* Default initialize the mtx struct. */ | |
82 | void mutex_init(struct mutex *mtx); | |
83 | /* | |
84 | * Initialize the mtx struct and set the process-shared rather than default | |
85 | * process-private attribute. | |
86 | */ | |
87 | void mutex_init_pshared(struct mutex *mtx); | |
88 | void mutex_destroy(struct mutex *mtx); | |
89 | ||
bfa339ce IR |
90 | void mutex_lock(struct mutex *mtx) EXCLUSIVE_LOCK_FUNCTION(*mtx); |
91 | void mutex_unlock(struct mutex *mtx) UNLOCK_FUNCTION(*mtx); | |
e57d8977 | 92 | /* Tries to acquire the lock and returns true on success. */ |
bfa339ce | 93 | bool mutex_trylock(struct mutex *mtx) EXCLUSIVE_TRYLOCK_FUNCTION(true, *mtx); |
e57d8977 PG |
94 | |
95 | /* Default initialize the cond struct. */ | |
96 | void cond_init(struct cond *cnd); | |
97 | /* | |
98 | * Initialize the cond struct and specify the process-shared rather than default | |
99 | * process-private attribute. | |
100 | */ | |
101 | void cond_init_pshared(struct cond *cnd); | |
102 | void cond_destroy(struct cond *cnd); | |
103 | ||
bfa339ce | 104 | void cond_wait(struct cond *cnd, struct mutex *mtx) EXCLUSIVE_LOCKS_REQUIRED(mtx); |
e57d8977 PG |
105 | void cond_signal(struct cond *cnd); |
106 | void cond_broadcast(struct cond *cnd); | |
107 | ||
108 | #endif /* __PERF_MUTEX_H */ |